Hi SCPOne,
As I understand it, you want to move the local Outlook calendar to Outlook Web App (OWA). If there is any misunderstanding, please correct me.
Based on my experience, you can see the calendar both in Outlook client and OWA (http://mail.office365.com/) after you add the calendar in Outlook client. You no need to move the local Outlook calendar to Outlook Web App (OWA). And data sync between local client Outlook and OWA is automatically.
Thanks,
Anna Shi